Therapeutic benefits can be achieved in some instances by providing an active agent to a specific, localized target tissue, instead of systemically. In this manner, the effect of the agent on the target tissue can be maximized while limiting side effects on other tissues. Therapeutic benefits can also be achieved by providing an active agent to a subject in a manner that provides controlled release of the active agent.
One approach to providing these benefits is to use a degradable matrix which retains an active agent before releasing it as the degradable matrix breaks down. Degradable matrices offer the advantage of being able to control the release rate of active agents that do not readily diffuse through non-degradable coatings. However, some types of degradable matrices may lack sufficient structural integrity and may develop structural defects such as cracks and gaps. In some cases, the lack of structural integrity can lead to portions of the matrix detaching from and falling off the substrate it is disposed on. As a result, degradable matrices may be unsuitable for use with some types of medical devices.
Accordingly, a need remains for active agent delivery and/or elution control matrices that can be used with a variety of active agents.